buffers.c revision 5ab1d0aceaffbf872d7f8ebea2a6655e25bf2390
1/* 2 * Mesa 3-D graphics library 3 * Version: 7.1 4 * 5 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a 8 * copy of this software and associated documentation files (the "Software"), 9 * to deal in the Software without restriction, including without limitation 10 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 11 * and/or sell copies of the Software, and to permit persons to whom the 12 * Software is furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included 15 * in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN 21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 */ 24 25 26/** 27 * \file buffers.c 28 * glReadBuffer, DrawBuffer functions. 29 */ 30 31 32 33#include "glheader.h" 34#include "buffers.h" 35#include "colormac.h" 36#include "context.h" 37#include "enums.h" 38#include "fbobject.h" 39#include "state.h" 40 41 42#define BAD_MASK ~0u 43 44 45/** 46 * Return bitmask of BUFFER_BIT_* flags indicating which color buffers are 47 * available to the rendering context (for drawing or reading). 48 * This depends on the type of framebuffer. For window system framebuffers 49 * we look at the framebuffer's visual. But for user-create framebuffers we 50 * look at the number of supported color attachments. 51 * \param fb the framebuffer to draw to, or read from 52 * \return bitmask of BUFFER_BIT_* flags 53 */ 54static GLbitfield 55supported_buffer_bitmask(const GLcontext *ctx, const struct gl_framebuffer *fb) 56{ 57 GLbitfield mask = 0x0; 58 59 if (fb->Name > 0) { 60 /* A user-created renderbuffer */ 61 GLuint i; 62 ASSERT(ctx->Extensions.EXT_framebuffer_object); 63 for (i = 0; i < ctx->Const.MaxColorAttachments; i++) { 64 mask |= (BUFFER_BIT_COLOR0 << i); 65 } 66 } 67 else { 68 /* A window system framebuffer */ 69 GLint i; 70 mask = BUFFER_BIT_FRONT_LEFT; /* always have this */ 71 if (fb->Visual.stereoMode) { 72 mask |= BUFFER_BIT_FRONT_RIGHT; 73 if (fb->Visual.doubleBufferMode) { 74 mask |= BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT; 75 } 76 } 77 else if (fb->Visual.doubleBufferMode) { 78 mask |= BUFFER_BIT_BACK_LEFT; 79 } 80 81 for (i = 0; i < fb->Visual.numAuxBuffers; i++) { 82 mask |= (BUFFER_BIT_AUX0 << i); 83 } 84 } 85 86 return mask; 87} 88 89 90/** 91 * Helper routine used by glDrawBuffer and glDrawBuffersARB. 92 * Given a GLenum naming one or more color buffers (such as 93 * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags. 94 */ 95static GLbitfield 96draw_buffer_enum_to_bitmask(GLenum buffer) 97{ 98 switch (buffer) { 99 case GL_NONE: 100 return 0; 101 case GL_FRONT: 102 return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT; 103 case GL_BACK: 104 return BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT; 105 case GL_RIGHT: 106 return BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT; 107 case GL_FRONT_RIGHT: 108 return BUFFER_BIT_FRONT_RIGHT; 109 case GL_BACK_RIGHT: 110 return BUFFER_BIT_BACK_RIGHT; 111 case GL_BACK_LEFT: 112 return BUFFER_BIT_BACK_LEFT; 113 case GL_FRONT_AND_BACK: 114 return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT 115 | BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT; 116 case GL_LEFT: 117 return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT; 118 case GL_FRONT_LEFT: 119 return BUFFER_BIT_FRONT_LEFT; 120 case GL_AUX0: 121 return BUFFER_BIT_AUX0; 122 case GL_AUX1: 123 return BUFFER_BIT_AUX1; 124 case GL_AUX2: 125 return BUFFER_BIT_AUX2; 126 case GL_AUX3: 127 return BUFFER_BIT_AUX3; 128 case GL_COLOR_ATTACHMENT0_EXT: 129 return BUFFER_BIT_COLOR0; 130 case GL_COLOR_ATTACHMENT1_EXT: 131 return BUFFER_BIT_COLOR1; 132 case GL_COLOR_ATTACHMENT2_EXT: 133 return BUFFER_BIT_COLOR2; 134 case GL_COLOR_ATTACHMENT3_EXT: 135 return BUFFER_BIT_COLOR3; 136 case GL_COLOR_ATTACHMENT4_EXT: 137 return BUFFER_BIT_COLOR4; 138 case GL_COLOR_ATTACHMENT5_EXT: 139 return BUFFER_BIT_COLOR5; 140 case GL_COLOR_ATTACHMENT6_EXT: 141 return BUFFER_BIT_COLOR6; 142 case GL_COLOR_ATTACHMENT7_EXT: 143 return BUFFER_BIT_COLOR7; 144 default: 145 /* error */ 146 return BAD_MASK; 147 } 148} 149 150 151/** 152 * Helper routine used by glReadBuffer. 153 * Given a GLenum naming a color buffer, return the index of the corresponding 154 * renderbuffer (a BUFFER_* value). 155 * return -1 for an invalid buffer. 156 */ 157static GLint 158read_buffer_enum_to_index(GLenum buffer) 159{ 160 switch (buffer) { 161 case GL_FRONT: 162 return BUFFER_FRONT_LEFT; 163 case GL_BACK: 164 return BUFFER_BACK_LEFT; 165 case GL_RIGHT: 166 return BUFFER_FRONT_RIGHT; 167 case GL_FRONT_RIGHT: 168 return BUFFER_FRONT_RIGHT; 169 case GL_BACK_RIGHT: 170 return BUFFER_BACK_RIGHT; 171 case GL_BACK_LEFT: 172 return BUFFER_BACK_LEFT; 173 case GL_LEFT: 174 return BUFFER_FRONT_LEFT; 175 case GL_FRONT_LEFT: 176 return BUFFER_FRONT_LEFT; 177 case GL_AUX0: 178 return BUFFER_AUX0; 179 case GL_AUX1: 180 return BUFFER_AUX1; 181 case GL_AUX2: 182 return BUFFER_AUX2; 183 case GL_AUX3: 184 return BUFFER_AUX3; 185 case GL_COLOR_ATTACHMENT0_EXT: 186 return BUFFER_COLOR0; 187 case GL_COLOR_ATTACHMENT1_EXT: 188 return BUFFER_COLOR1; 189 case GL_COLOR_ATTACHMENT2_EXT: 190 return BUFFER_COLOR2; 191 case GL_COLOR_ATTACHMENT3_EXT: 192 return BUFFER_COLOR3; 193 case GL_COLOR_ATTACHMENT4_EXT: 194 return BUFFER_COLOR4; 195 case GL_COLOR_ATTACHMENT5_EXT: 196 return BUFFER_COLOR5; 197 case GL_COLOR_ATTACHMENT6_EXT: 198 return BUFFER_COLOR6; 199 case GL_COLOR_ATTACHMENT7_EXT: 200 return BUFFER_COLOR7; 201 default: 202 /* error */ 203 return -1; 204 } 205} 206 207 208/** 209 * Called by glDrawBuffer(). 210 * Specify which renderbuffer(s) to draw into for the first color output. 211 * <buffer> can name zero, one, two or four renderbuffers! 212 * \sa _mesa_DrawBuffersARB 213 * 214 * \param buffer buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc. 215 * 216 * Note that the behaviour of this function depends on whether the 217 * current ctx->DrawBuffer is a window-system framebuffer (Name=0) or 218 * a user-created framebuffer object (Name!=0). 219 * In the former case, we update the per-context ctx->Color.DrawBuffer 220 * state var _and_ the FB's ColorDrawBuffer state. 221 * In the later case, we update the FB's ColorDrawBuffer state only. 222 * 223 * Furthermore, upon a MakeCurrent() or BindFramebuffer() call, if the 224 * new FB is a window system FB, we need to re-update the FB's 225 * ColorDrawBuffer state to match the context. This is handled in 226 * _mesa_update_framebuffer(). 227 * 228 * See the GL_EXT_framebuffer_object spec for more info. 229 */ 230void GLAPIENTRY 231_mesa_DrawBuffer(GLenum buffer) 232{ 233 GLbitfield destMask; 234 GET_CURRENT_CONTEXT(ctx); 235 ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */ 236 237 if (MESA_VERBOSE & VERBOSE_API) { 238 _mesa_debug(ctx, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(buffer)); 239 } 240 241 if (buffer == GL_NONE) { 242 destMask = 0x0; 243 } 244 else { 245 const GLbitfield supportedMask 246 = supported_buffer_bitmask(ctx, ctx->DrawBuffer); 247 destMask = draw_buffer_enum_to_bitmask(buffer); 248 if (destMask == BAD_MASK) { 249 /* totally bogus buffer */ 250 _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffer(buffer)"); 251 return; 252 } 253 destMask &= supportedMask; 254 if (destMask == 0x0) { 255 /* none of the named color buffers exist! */ 256 _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffer(buffer)"); 257 return; 258 } 259 } 260 261 /* if we get here, there's no error so set new state */ 262 _mesa_drawbuffers(ctx, 1, &buffer, &destMask); 263 264 /* 265 * Call device driver function. 266 */ 267 if (ctx->Driver.DrawBuffers) 268 ctx->Driver.DrawBuffers(ctx, 1, &buffer); 269 else if (ctx->Driver.DrawBuffer) 270 ctx->Driver.DrawBuffer(ctx, buffer); 271} 272 273 274/** 275 * Called by glDrawBuffersARB; specifies the destination color renderbuffers 276 * for N fragment program color outputs. 277 * \sa _mesa_DrawBuffer 278 * \param n number of outputs 279 * \param buffers array [n] of renderbuffer names. Unlike glDrawBuffer, the 280 * names cannot specify more than one buffer. For example, 281 * GL_FRONT_AND_BACK is illegal. 282 */ 283void GLAPIENTRY 284_mesa_DrawBuffersARB(GLsizei n, const GLenum *buffers) 285{ 286 GLint output; 287 GLbitfield usedBufferMask, supportedMask; 288 GLbitfield destMask[MAX_DRAW_BUFFERS]; 289 GET_CURRENT_CONTEXT(ctx); 290 ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); 291 292 if (!ctx->Extensions.ARB_draw_buffers) { 293 _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB"); 294 return; 295 } 296 if (n < 1 || n > (GLsizei) ctx->Const.MaxDrawBuffers) { 297 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawBuffersARB(n)"); 298 return; 299 } 300 301 supportedMask = supported_buffer_bitmask(ctx, ctx->DrawBuffer); 302 usedBufferMask = 0x0; 303 304 /* complicated error checking... */ 305 for (output = 0; output < n; output++) { 306 if (buffers[output] == GL_NONE) { 307 destMask[output] = 0x0; 308 } 309 else { 310 destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]); 311 if (destMask[output] == BAD_MASK 312 || _mesa_bitcount(destMask[output]) > 1) { 313 _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffersARB(buffer)"); 314 return; 315 } 316 destMask[output] &= supportedMask; 317 if (destMask[output] == 0) { 318 _mesa_error(ctx, GL_INVALID_OPERATION, 319 "glDrawBuffersARB(unsupported buffer)"); 320 return; 321 } 322 if (destMask[output] & usedBufferMask) { 323 /* can't specify a dest buffer more than once! */ 324 _mesa_error(ctx, GL_INVALID_OPERATION, 325 "glDrawBuffersARB(duplicated buffer)"); 326 return; 327 } 328 329 /* update bitmask */ 330 usedBufferMask |= destMask[output]; 331 } 332 } 333 334 /* OK, if we get here, there were no errors so set the new state */ 335 _mesa_drawbuffers(ctx, n, buffers, destMask); 336 337 /* 338 * Call device driver function. 339 */ 340 if (ctx->Driver.DrawBuffers) 341 ctx->Driver.DrawBuffers(ctx, n, buffers); 342 else if (ctx->Driver.DrawBuffer) 343 ctx->Driver.DrawBuffer(ctx, buffers[0]); 344} 345 346 347/** 348 * Helper function to set the GL_DRAW_BUFFER state in the context and 349 * current FBO. 350 * 351 * All error checking will have been done prior to calling this function 352 * so nothing should go wrong at this point. 353 * 354 * \param ctx current context 355 * \param n number of color outputs to set 356 * \param buffers array[n] of colorbuffer names, like GL_LEFT. 357 * \param destMask array[n] of BUFFER_BIT_* bitmasks which correspond to the 358 * colorbuffer names. (i.e. GL_FRONT_AND_BACK => 359 * BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT). 360 */ 361void 362_mesa_drawbuffers(GLcontext *ctx, GLuint n, const GLenum *buffers, 363 const GLbitfield *destMask) 364{ 365 struct gl_framebuffer *fb = ctx->DrawBuffer; 366 GLbitfield mask[MAX_DRAW_BUFFERS]; 367 368 if (!destMask) { 369 /* compute destMask values now */ 370 const GLbitfield supportedMask = supported_buffer_bitmask(ctx, fb); 371 GLuint output; 372 for (output = 0; output < n; output++) { 373 mask[output] = draw_buffer_enum_to_bitmask(buffers[output]); 374 ASSERT(mask[output] != BAD_MASK); 375 mask[output] &= supportedMask; 376 } 377 destMask = mask; 378 } 379 380 if (n == 1) { 381 GLuint buf, count = 0; 382 /* init to -1 to help catch errors */ 383 fb->_ColorDrawBufferIndexes[0] = -1; 384 for (buf = 0; buf < BUFFER_COUNT; buf++) { 385 if (destMask[0] & (1 << buf)) { 386 fb->_ColorDrawBufferIndexes[count] = buf; 387 count++; 388 } 389 } 390 fb->ColorDrawBuffer[0] = buffers[0]; 391 fb->_NumColorDrawBuffers = count; 392 } 393 else { 394 GLuint buf, count = 0; 395 for (buf = 0; buf < n; buf++ ) { 396 if (destMask[buf]) { 397 fb->_ColorDrawBufferIndexes[buf] = _mesa_ffs(destMask[buf]) - 1; 398 fb->ColorDrawBuffer[buf] = buffers[buf]; 399 count = buf + 1; 400 } 401 else { 402 fb->_ColorDrawBufferIndexes[buf] = -1; 403 } 404 } 405 /* set remaining outputs to -1 (GL_NONE) */ 406 while (buf < ctx->Const.MaxDrawBuffers) { 407 fb->_ColorDrawBufferIndexes[buf] = -1; 408 fb->ColorDrawBuffer[buf] = GL_NONE; 409 buf++; 410 } 411 fb->_NumColorDrawBuffers = count; 412 } 413 414 if (fb->Name == 0) { 415 /* also set context drawbuffer state */ 416 GLuint buf; 417 for (buf = 0; buf < ctx->Const.MaxDrawBuffers; buf++) { 418 ctx->Color.DrawBuffer[buf] = fb->ColorDrawBuffer[buf]; 419 } 420 } 421 422 ctx->NewState |= _NEW_COLOR; 423} 424 425 426/** 427 * Like \sa _mesa_drawbuffers(), this is a helper function for setting 428 * GL_READ_BUFFER state in the context and current FBO. 429 * \param ctx the rendering context 430 * \param buffer GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc. 431 * \param bufferIndex the numerical index corresponding to 'buffer' 432 */ 433void 434_mesa_readbuffer(GLcontext *ctx, GLenum buffer, GLint bufferIndex) 435{ 436 struct gl_framebuffer *fb = ctx->ReadBuffer; 437 438 if (fb->Name == 0) { 439 /* Only update the per-context READ_BUFFER state if we're bound to 440 * a window-system framebuffer. 441 */ 442 ctx->Pixel.ReadBuffer = buffer; 443 } 444 445 fb->ColorReadBuffer = buffer; 446 fb->_ColorReadBufferIndex = bufferIndex; 447 448 ctx->NewState |= _NEW_PIXEL; 449} 450 451 452 453/** 454 * Called by glReadBuffer to set the source renderbuffer for reading pixels. 455 * \param mode color buffer such as GL_FRONT, GL_BACK, etc. 456 */ 457void GLAPIENTRY 458_mesa_ReadBuffer(GLenum buffer) 459{ 460 struct gl_framebuffer *fb; 461 GLbitfield supportedMask; 462 GLint srcBuffer; 463 GET_CURRENT_CONTEXT(ctx); 464 ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); 465 466 if (MESA_VERBOSE & VERBOSE_API) 467 _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer)); 468 469 fb = ctx->ReadBuffer; 470 471 if (MESA_VERBOSE & VERBOSE_API) 472 _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer)); 473 474 if (fb->Name > 0 && buffer == GL_NONE) { 475 /* This is legal for user-created framebuffer objects */ 476 srcBuffer = -1; 477 } 478 else { 479 /* general case / window-system framebuffer */ 480 srcBuffer = read_buffer_enum_to_index(buffer); 481 if (srcBuffer == -1) { 482 _mesa_error(ctx, GL_INVALID_ENUM, 483 "glReadBuffer(buffer=0x%x)", buffer); 484 return; 485 } 486 supportedMask = supported_buffer_bitmask(ctx, fb); 487 if (((1 << srcBuffer) & supportedMask) == 0) { 488 _mesa_error(ctx, GL_INVALID_OPERATION, 489 "glReadBuffer(buffer=0x%x)", buffer); 490 return; 491 } 492 } 493 494 /* OK, all error checking has been completed now */ 495 496 _mesa_readbuffer(ctx, buffer, srcBuffer); 497 498 /* 499 * Call device driver function. 500 */ 501 if (ctx->Driver.ReadBuffer) 502 (*ctx->Driver.ReadBuffer)(ctx, buffer); 503} 504 505 506#if _HAVE_FULL_GL 507 508/** 509 * XXX THIS IS OBSOLETE - drivers should take care of detecting window 510 * size changes and act accordingly, likely calling _mesa_resize_framebuffer(). 511 * 512 * GL_MESA_resize_buffers extension. 513 * 514 * When this function is called, we'll ask the window system how large 515 * the current window is. If it's a new size, we'll call the driver's 516 * ResizeBuffers function. The driver will then resize its color buffers 517 * as needed, and maybe call the swrast's routine for reallocating 518 * swrast-managed depth/stencil/accum/etc buffers. 519 * \note This function should only be called through the GL API, not 520 * from device drivers (as was done in the past). 521 */ 522 523void _mesa_resizebuffers( GLcontext *ctx ) 524{ 525 ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx ); 526 527 if (MESA_VERBOSE & VERBOSE_API) 528 _mesa_debug(ctx, "glResizeBuffersMESA\n"); 529 530 if (!ctx->Driver.GetBufferSize) { 531 return; 532 } 533 534 if (ctx->WinSysDrawBuffer) { 535 GLuint newWidth, newHeight; 536 GLframebuffer *buffer = ctx->WinSysDrawBuffer; 537 538 assert(buffer->Name == 0); 539 540 /* ask device driver for size of output buffer */ 541 ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight ); 542 543 /* see if size of device driver's color buffer (window) has changed */ 544 if (buffer->Width != newWidth || buffer->Height != newHeight) { 545 if (ctx->Driver.ResizeBuffers) 546 ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight ); 547 } 548 } 549 550 if (ctx->WinSysReadBuffer 551 && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) { 552 GLuint newWidth, newHeight; 553 GLframebuffer *buffer = ctx->WinSysReadBuffer; 554 555 assert(buffer->Name == 0); 556 557 /* ask device driver for size of read buffer */ 558 ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight ); 559 560 /* see if size of device driver's color buffer (window) has changed */ 561 if (buffer->Width != newWidth || buffer->Height != newHeight) { 562 if (ctx->Driver.ResizeBuffers) 563 ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight ); 564 } 565 } 566 567 ctx->NewState |= _NEW_BUFFERS; /* to update scissor / window bounds */ 568} 569 570 571/* 572 * XXX THIS IS OBSOLETE 573 */ 574void GLAPIENTRY 575_mesa_ResizeBuffersMESA( void ) 576{ 577 GET_CURRENT_CONTEXT(ctx); 578 579 if (ctx->Extensions.MESA_resize_buffers) 580 _mesa_resizebuffers( ctx ); 581} 582 583 584/* 585 * XXX move somewhere else someday? 586 */ 587void GLAPIENTRY 588_mesa_SampleCoverageARB(GLclampf value, GLboolean invert) 589{ 590 GET_CURRENT_CONTEXT(ctx); 591 592 if (!ctx->Extensions.ARB_multisample) { 593 _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleCoverageARB"); 594 return; 595 } 596 597 ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx ); 598 ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0); 599 ctx->Multisample.SampleCoverageInvert = invert; 600 ctx->NewState |= _NEW_MULTISAMPLE; 601} 602 603#endif /* _HAVE_FULL_GL */ 604 605 606 607/** 608 * Initialize the context's multisample state. 609 * \param ctx the GL context. 610 */ 611void 612_mesa_init_multisample(GLcontext *ctx) 613{ 614 ctx->Multisample.Enabled = GL_TRUE; 615 ctx->Multisample.SampleAlphaToCoverage = GL_FALSE; 616 ctx->Multisample.SampleAlphaToOne = GL_FALSE; 617 ctx->Multisample.SampleCoverage = GL_FALSE; 618 ctx->Multisample.SampleCoverageValue = 1.0; 619 ctx->Multisample.SampleCoverageInvert = GL_FALSE; 620} 621